Deep well pump apparatus



A. G. BODINE, JR

DEEP WELL PUMP APPARATUS May 22, 1951 2 Sheets-Sheet 1 Filed March 8, 1948 [WEA/rae. Mezfgouh.

irme/w74 A. G. BODINE, JR

DEEP WELL PUMP APPARATUS Filed March 194s 2 Sheets-Sheet 2 Patented May 22, n1951 UNITED 'STATES PATENT OFFICE i 9,-Claims. l I This invention-*relates generally 'to deep' well pumps, andmore particularly to improvements in deep well pumps operated by periodic waves of :tension and compression at sonic frequencies in an'elasticeolumn such as the pump tubing or a rod string.

The `present application. disclosesimprovements inva `certain :class 'of pumps broadlyfdiscl'osed in mycopending application entitled Method and Apparatus .for Pumping, *Serial No. 761,456, viileol July 17', 1947, andaliowed October 22, 1947, now Patent'sNo. 2,444,912. In said application Iv disclosed severalzembodimentsf-of the type of pump to which` the present-invention broadly pertains, including forms in whichA the Vwave motion `is transmitteddown an'elastic tubing, and other forms Vinwliich the wave motion is transmitted down an elastic rod string. Taking the first class as representative, the elastic tubing may typically be `suspended from* awspring-mounted platform at the 'ground surface. An Yeccentr'ic'ally weighted flywheel is mounted in bearings supported on the platform andserves', whendriven at high rotational velocity, .to .longitudinally vreciprocate the upper end of' the tubing' 1in such a manner as to transmit down it alternate deformation waves oi tension and compression. -Points along the tubing are thus set into vertical oscillation. Preferably, the waves are generated at such a frequency relative to the'length of the tubing that the tubing is resonated and` there is produced therein,in a manner weil known to those familiar with the acoustic art,` a standing wave characterized by alternatevregions of maximum and minimum oscillatory movement. A `fluid impelling the check valve means is mounted in the tubing, Apreferably at a point of` maximum oscillatorymovement (velocity anti-node) and participates in the vertical oscillations of the portion-'of the tubing in which it is mounted, where byk increments of fluid are pumped upwardly past the 'check'.valvev'to be elevated in the tubing. Additional uid impelling and check valve means mayadvan'tageouslybe located at other velocity anti-nodes in the tubing, `as explained in my said earlier application.

In such a pump "it is unavoidable that the elastic waves generated 'at the ground surface become attenuated and lose some of their power asl they progress down the pump tubing. These losses result not only from friction within the tubing material as it is flexed by the passage of thewave, but also from `friction between the tubing lsurfaces and the well liquid, and at some points through contact with the walls of the well hole.

Since the usual Well tubing is luniformlin its wave transmission characteristics.throughout its length, the attenuation of *power results a reduction in displacement amplitude of the check valve near the bottom of the well. The :pumping efliciency may be thus considerablyimpaired.

Withv 'a'pump tubing having a number' of check valves, as mentioned above, the quantity of liquid pumped will be somewhat limited to that displaced by 'the check valve having the least movement, 'especially if such valve be at 'the intake end. For instance, the check valve located at the lowestpoint in the well may receive a vertical oscillation which is less than one-half the oscillation of check valves near the surface.

It is one of "the major objectives of the inven tion to overcome fthe disadvantages of power attenuation in such pumps. VThe achievement of this Objectis made `possible by the fact that the displacement amplitude at any point along the tubing vfor a wave of given powerwill be inversely proportional to the longitudinal Adynamic stiffness of the tubingin that region. If the tubing is relatively 'stili under `conditions of wave' propagation,V that is, if'the ratio'of periodic longitudinal stress at` agiven vsectionl vof the tubing to the oscillation velocity at that section .is very high, 'the transmission of elastic waves of a 'given power will produce a relatively small longitudinal displacement amplitude. In the language of thelacou'stic art, such a 'tubing is said to have a high acoustic impedance. If, 'on the other hand, the longitudinal dynamic stiffness of 'the tubing is'relatively small, vthat is, the ratio of longitudinal periodic 'stress at a given section to the oscillation velocity at that "section is relatively low, the transmission through the tubing of a wave kof the same power will pro duce a relatively large longitudinal displacement of each section of the tubing. In the language of the acoustic art, such a tubing is said to have low acoustic impedance.

Broadly speaking, the primary objectof the invention'is accomplished by employing a tubing section of'relatively high` impedance in the upper portion of the well `'and atubing section of sub-` stantially lesser impedance in the lower portion of the well. In a deep well, I 'may' employ a long stand of tubing in which the impedance diminishes from' lsection to section throughout its length; having the maximum atthe upper end and a minimum at 'the lowest section. For' reasons that should now be evident, the wave increases in amplitude each time it leaves anupper tubing section of one acoustic impedance and enters a lower tubing section of reduced acoustic impedance.

However the invention is not restricted to mere compensation of wave impairment owing to power attenuation along the elastic column. On the contrary, it isa furtherl purpose and accomplishment to use acolumn section of reduced impedance at the lower end to increase the pumping stroke substatnially above what would be achieved where there no attenuation to contend with. In other words, it is a further object of the invention to provide the pump with an elastic column whose lower or pumping end will oscillate at greater amplitude than will its upper or power.

receiving end.

The invention is not limited to any particular means for diminishing the impedance of the tubing. A rigorous expression for the desired reduction of uniformly distributed impedance would state that the mathematical product of mass per foot times the speed of sound along the member should be reduced in order to reduce the impedance. This may beaccomplished, for instance, by reducing the wall thickness of the tubing in the lower part of the well, or by using amaterial having a lower modulus of elasticity, or both, or in any other way in which the ratio of longitudinal dynamic load to the longitudinal deformation particle velocity of the tubing is diminished. For some special cases it may be desirable to reduce the relative modulus by forming the lower portion of the pump tubing in accordion fashion, or by making other special arrangements for reduction in the acoustic impedance of the tubing. Moreover, the wave motion may be transmitted to the pumping member in the bottom of the well via an elastic column other than the tubing, for example, via a string of sucker rods.

The invention will be better understood from a 'consideration'of several illustrative embodiments thereof, reference for this purpose being had to the accompanying drawings, in which:

Figure 1 is a partly elevational and partially longitudinal. sectional viewof one embodiment of the invention;

Figure 2 is a longitudinal sectional View of a desirable'means for coupling two tubing lengths of Adiffering wall thickness;

Figure 3 is a View partly in longitudinal medial section, and partly in elevation, of another embodiment of the invention;

VFigure 4 is an enlarged longitudinal sectional View of the lower end portion of the pump of Figure 3; and

Figure 5 is a'partly elevational and partly longitudinal sectional View of another embodiment of the invention.

In Figures 1 and 2 an oil well bore is indicated by the letter W, and a well casing within said bore by numeral I0, the lower end portion of the casing adjacent the productive formation being understood to be perforated in the usual manner. The stand of tubing II, understood as composed of elastic material, as steel, is suspended in well bore W from platform I2, its lower endl reaching downwardly to the region of liquid L to be pumped from the well bore. Tubing II is formed in pump tubing sections of usual lengths coupled together as by use of conventional coupling collars, such as C. Platform I 2 is resiliently mounted o n vertical coil springs I3 standing on platform I4 which isinturn supportedron the ground surface. The lower end portion of the tubing IIis controlled by a check valve I5, and its upper end has delivery pipe I5a.

,Mounted on .platform I2, or on the upper end of tubing II extending thereabove, is a housing I6 containing a means for vertically Vibrating` the. platform I2, and thereby exerting a vertical oscillating force upon the upper end of the tubing I I. The means for generating vibratons'con- 761,456, and the one illustrated in Figure 1 of the present case is of that general type, having meshing oppositely rotating .spur gears I'I carrying eccentric weights I8 which balance out horizontal vibrations but are additive to produce a substantial resultant oscillatory force in a vertical direc-` tion. The driving pulley of the 'sound wave gen'- erator G, mounted on the shaft for one of the spur ygears, is driven by electric motor I9 through belt 20.

The oscillating force applied to the upper end of the elastic tubing II by sound wave generator G causes the upper end portion of the tubing to be alternately elongated and shortened. These deformations of the elastic tubing cause alternate waves of tension and compression to be launched down the tubing, traveling in the material of the tubing Ywith the speed of sound, and hence being referred to as sound waves.

ciprocated in a bodily manner. On the contrary, the vertically 'oscillating forces applied to the upper end of the tubing by the generator G are of such high frequency (for instance, though without implying any limitation on the invention, 20 cycles per second for a 4,000 ft. tubing) as to make that ytype of operation impossible. Instead, longitudinal elastic deformation waves of compression and tension, of wave length usually shorter than the length of the tubing, travel down the tubing, causing each transverse sec-y tion thereof to oscillate vertically with each pas'- sage of a wave. Since the frequency is suchas compared with the length of the tubing as to provide a wave length along the tubing which is short relative to the length of the pipe, vertically spaced portions of the tubing may actually be traveling in contrary directions'at a given instant. For purposes of maximum efficiency, it is desirable that the frequency of the Sound wave generator and the length of the tubing should be so related that the tubing stand is longitudinally resonated, which is accomplished by driving the sound wave generator at a resonant frequency of the tubing string. Such operation establishes a standing wave along the tubing, with one or more velocity nodes at tubing sections a halfwave length apart. At these tubing sections, thev amplitude of Vertical oscillation is substantially zero. At points half-way between these velocity nodes there will appear regions of maximum amplitude of Vertical oscillation. For the purpose of the embodiment of Figure 1, it is desirablel to have the check valve I5 at a point of substantialor maximum oscillation, and hence it is de-y sirable, though not essential, to establisha velocity anti-node region near or at said juncture.

vThe tubing II thus undergoes vertical oscillation in amounts which may differ from section to section along its length. located at a velocity anti-node, the amplitude for this vertical oscillationwill be maximized at the location of the check valve. During each oscillation of the check valve I5, a small incre- It must be understood that the tubing is not vertically re-.

If the valve I5 isv '1 mentzof well iluid -travelsupwardly sin the pump tubin'gpast check valve 15, to kbe elevated inthe pump tubing and eventually discharged -yia'a delivery tube indicated at 22. Consideringthe checkvalve l5 in'more particular, it comprises typically a valve seat ring 23 rigidly secured within `thepuinp tubing, saidring having passageway 24 whose top end forms a seat for ,check valve' ball 25; Functionally considered, this check valve consists of alluid impelling and check valve means operated by the described vertical oscillations of the portion of Athe pump tubing to which the v ring 23i is secured. On each down stroke of .the ring 23, occurringwith an accelera-- tion exceeding gravity, a small increment of-well iluidt is displaced thereby t0 'ilcw Vupwardly through 'passageway 24 and past the unseated' valve ball 25 to the liquid column thereabove, itbeing understood that `the check valve ball 25 will descend at a slower rate underxthe acceleration of* gravity than will the valve. seat ring 23' driven by the oscillating pump tubing, so asto open the passage 24 on the down stroke of said ring '23. Further, the` described down stroke ofthe ring 23 tends to leave a void in the liquid column thereabove, which has the effect of causing well fluid to be sucked upwardly through the passage 24. On the succeeding .upstroke of the val-ve seat ring 23, the valve ball 25 seats at theiupper end'of passage 24, and the entire liquid column above is elevated accordingly. This operationvis more fully discussed in my aforementioned prior application Serial No. 761,456.

The vertical displacement amplitude of any given section of the pump tubing will be determined by the stiffness or impedance of the tubing inthat region. Since the upper portion of thepump tubing must carry'the entire weight of the tubing stand hanging below, it is necessarily relatively thick-walled and stiff, its impedance is high, and the displacement amplitude is therefore small. Moreover, since the power transmitted down the pump tubing must inevitably experience some attenuation with increasing depth, it follows that the displacement amplitude of a section of the tubing in the lower portion thereof will necessarily be substantially smaller than in the upper portion if the tubing is of uniform cross-sectionr and material throughout its length. The lower portion of the tubing, however, carries much less load than the upper portion,` and may, therefore, be of substantially lighter and more compliant construction.

, In accordance with the form of the invention of Figure 1 the power attenuation described in the preceding paragraph is compensated by constructing the pump tubing of an upper relatively thick-walled section 352 coupled as by collar C to a lower thin-walled section 3|, the lower section 3l thus having a reduced cross-sectional area as compared with upper section 3U. The longitudinal waves of compression and tension (sound waves) which travel down thick-walled high iinpedance tubing section 30 with comparatively small vertical displacement amplitude of its successive transverse sections will, upon entering relatively lower impedance thin-walled section 3 I produce comparatively large displacement amplitude of the successive transverse sections thereof, and the amplitude of vertical oscillation of check valve seat 23 will accordingly be greater than would have been thecase had the tubing section 3l been of the same wall thickness as tubing section 3U. Such augmented displacement amplitude of the fluid displacing and check valve' means constitu-ted in this case by the-valveseat ring 234 and valve ball -25 will quite obviously result in a. correspondingly improved pumping rate.

Considering the embodiment of Figure l instill more particularyit will be evident that the thickwalled pump'tubing section 3l! may be made up of a number of sections of such thick-walled tubing, all coupled together, as by use of usual coupling collars y(not shown) and such a group of thick-walled tubing sections are designated gen` erally by the numeral 3l). In rlike manner, the lower thin-walled portion 3l of the tubing may; be made up of a number of tubing lengths of similar construction, coupled together by usual coupling -collars (not shown). ther be understood that instead of having one relatively thick-walled section and one relatively thin-walled section, additional graduations mayv be employed if desired. That is to say, vthere may be more than two tubing sections of reduced wall thickness and/or stiiness in a downward direction, the two here shown being however suiT-' ciently illustrative of the invention.

It will thus be seen that even though there be a substantial degree of wave amplitude attenuation between the generator at the top of ther tubing and the lower end of the thick-walled tubing section, the wave amplitude will be augmented upon reaching the thin-walled, low rimpedance tubing section below, thereby increasing the pumping stroke. In some cases, the augmenting of the pumping stroke may necessarily be only suncient to compensate for wave attenuation. However, as has been made apparent, the scope of the invention is not restricted to compensation of wave attenuation, but on the contrary, by'

choice of a suniciently compliant lower tubing section, the'vibration amplitude ofthe pumping member (the check-valved ring 23 of Figure l)v may be made not only as great, but even greater than that occurring within the upper end portion of the pump tubing, immediately adjacent the generator itself. Y

Further reduction in the stiffness of the lower tubing section may be accomplished by using a material for the purpose of the lower tubing section which has a lower Amodulus of elasticity than does the upper tubing section. Vlit will also` be evident that a reduction in stiffness of the lower tubing section, in accordance with the aims of the invention, may be accomplished by using for the lower tubing section a material of reduced modulus of elasticity, even though the wall thickness of the tubing remain uniformthroughout the upper and lower sections. It is, of course, true that theinvention can also be practicedgwi'th horizontal pumping, in which event springs I3 are no longer necessary.

vFigure 2 shows the use of a quarter-wave tubing section 4B connecting an upper thick-walled intermediate wall thickness and stiffness. By having its length a quarter-wave length, measured along the tubing, of a wave generated at the tubing'by the vibration generator, impedances are better matched and the transfer of wave energy from the thick-walled to the thin-walled tubing sections is made to occur with improved efficiency.V

Figures 3 and 4 show a modification, employing a relatively short lower tubing section which has been corrugated circumferentially to giveit sub.-

And it will fur j corresponding components.

stantially reduced stiffness (reduced impedance), and consequently very much increased vibration amplitude. In this embodiment the well casing, vibration generator, pump tubing and mounting therefor, may be as in Figure 1, and corresponding reference numerals, but with the suiix a, added, will be used in Figures 3 and 4 to identify The portions of the pump of Figures 3 and 4 obviously corresponding to Figure l will not require further description. Suspended from the lower end of elastic pump tubing I Ia is an elastic tubing section 58 which is folded or corrugated in a bellows-like or accordion fashion, thereby greatly decreasing its longitudinal stiffness, as well as the wave-length of a longitudinal wave traversing it. The elastic section 58 is made up of a multiplicity of outwardlyfolded bellows sections I, each iiange-connected to the next, and preferably with intervening valve plates 52 having central ports 53 controlled by check valve balls 54.

In operation, the pump tubing la will be subjected to longitudinal wave motion of the type previously described in connection with Figure 1 and the lower end thereof coupled to corrugated pipe section 50 will consequently impart corresponding vertical reciprocation, at the vibration frequency of generator Ga, to the upper end of said section 50. Because of the very greatly reduced stiffness per unit length of the corrugated section 50, the latter will, while transmitting the longitudinal wave from its upper to its lower end, be subjected to a vibration amplitude of greatly increased magnitude. Each valve 54 operating in conjunction with the ported valve plate 52 will pump fluid upwardly just as described in connection with Figure 1. On each down stroke, uid displaced by the downwardly traveling plate 52 Will be forced yupwardly through passage 53 and past valve ball 54. On each upstroke, the valve 54 will seat, causing the column of uid to be elevated.

The system of Figures 3 and 4 thus, in common with that of Figures 1 and 2, has the advantage of a magnied vertical oscillation of the valve carrying members, greatly increasing the pumping stroke over what would be accomplished were the valve carrying member to be directly and rigidly connected to the lower end of the pump tubing IIa.

In the embodiment of the invention disclosed in Figures 1 to 4, inclusive, the sound waves are transmitted to the pumping member by way 'of the pump tubing serving asY the elastic wave transmission column. As fully explained in my earlier mentioned application Serial No. 761,456, the wave motion may be transmitted to the pumping member by any suitable elastic column, and for this purpose not only the pump tubing is available, but in many instances a rod string may be employed. Several versions of the latter class are disclosed in my earlier application. Figure 5 of the present case illustrates one embodiment of this general type, and is illustrative of the various types of my pump in which a rod string serves as the wave transmission medium. The pump tubing 88 is suspended within casing 8|, the upper end of tubing 8|! being screwed into tubing head 82, to which is secured casing head 83. Mounted on tubing head 82 is platform 88 carrying upstanding coil springs 89 whose upper ends support a plate 90 from which is hung suspension rod 9| extending downwardly into tubing head 85, and into the lower end of which is screwed the upper end of elastic sucker rod string 94. A stuffing' box 96 surrounds suspension rod` 9| and is fitted tightly in platform 88, and the tubing head has production outlets 91 as indicated.

The weight of the sucker rod string is thus transferred by rod 9| to plate 90, and thus to strings 89 which are in turn supported through platform 88 from tubing head 82, and the casing head 83 which carries tubing head 82 will be understood to be suitably supported to carry the load thus placed upon it by any appropriate supporting means, not shown.

Mounted on the top end of rod 9| is a sound wave generator |88 which may be of exactly the same general character as that disclosed in the previously described figures and hence need not be described in detail. Suflice'it to say that this generator, like those previously described, is adapted to generate vibrations in a vertical direction, which are exerted upon the upper end of rod 9|, and are thence transmitted to sucker rod string 98.

The lower end of rod string 90 is screwed into a fluid impelling and check valve unit I8, which may be of various types, but is here shown in the simple form of a pump plunger I I I having Vertical intake bore I|2 provided at its top end with a seat for a check valve ball |I3, and having upwardly discharging passageways I I4 leading from valve ball chamber II5. This plunger may be rigidly secured to the pump tubing, in which case its vertical reciprocation must be participated in by the pump tubing. However, the plunger III may also be slidably tted in the pump tubing, and thus reciprocated vertically relative to the pump tubing walls. Y

In operation, the generator |80 is set into ver. tical oscillation and transmits longitudinal elastic.

deformation waves of compression and expansion down the length of the spring-supported elastic` sucker rod string 96, the springs 89 oscillating in step with the Vibration frequency of the genera-tor, and the waves of compression and` ex.-A

pansion being continuously transmitted down the sucker rod string to the check valve and fluid impelling unit III). It will be understood that the sucker rod portion at the unit I|0 will be set into vertical oscillation, and that on each down stroke of the plunger II I, which will occurv at an acceleration greater than gravity, the' plunger will displace well liquid upwardly through the passageway I I2 past the bore I3 and into the valve chamber |I5, while on each up stroke of the plunger, the valve ball will become seated and the well liquid in the chamber I I5 as well as the liquid column above will be elevated. It should be understood that this operation will occur whether or not the plunger III is rigidly secured to the pump tubing. If the plunger is rigidly connected to the pump tubing the only difference is that sufficient power must be transmitted down the sucker rod string to vibrate the lower portion of the pump tubing along with the.y plunger. l

As with the other embodiments, the amplitude of the transmitted vibrations becomes attenuated down the elastic column, in this case, the sucker rod string. To compensate for this effect, the sucker rod string is made up to two or more sections, of progressively-increasing compliance (reduced acoustic impedance) in a downward direction. Thus the string may comprise an upper section 98a of a certain degree of stiffness, and a,

- lower section 98h of reduced stiffness, the two 75 sections being shown to be joined by coupling |20.

l ntlfle-'fpresent instance, tliflower string elastic column at thelocationj'of the oscillatory fluid impelling 'and che'ckvalve means; ist augmented to compensate for the attenuation which would otherwise undesirably reduce the pumping stroke.

There have now been illustrated several distinct embodiments of the invention. It will be understood that these are not exhaustive, but only illustrative of the broad invention in several of its forms, and that the invention is therefore not to be limited to such forms, but only in accordance with the spirit and scope of the appended claims.

I claim:

l. A deep well pump which includes: an oscillatory fluid impelling pumping member adapted for placement in the well, a sonic wave generator located at the ground surface, and an elastic column of solid material operatively interconnecting said sonic wave generator and said oscillatory fluid impelling pumping member, said column being adapted to transmit alternate waves of compression and tension longitudinally therethrough from said generator to said pumping member, and said elastic column being constructed to have a reduction in stiffness per unit length in a lower portion thereof in order to compensate for wave amplitude attenuation.

2. A deep well pump which includes: an oscillatory fluid impelling pumping member adapted for placement in the well, a sonic wave generator located at the ground surface, and an elastic column of solid material operatively interconnecting said sonic wave generator and said oscillatory uid impelling pumping member, said column being adapted to transmit alternate waves of cornpression and tension longitudinally therethrough from said generator to-'said pumping member, said elastic column including an upper section of s a given stiffness per unit length against longitudinal deflection, and a lower section of a lesser stiffness' per unit length against longitudinal deection, whereby to augment the amplitude of longitudinal oscillation of the lower section of the elastic column.

3.. A deep well pump which includes: an oscillatory fluid impelling pumping member adapted for placement in the well, a sonic wave generator located at the ground surface, and an elastic column of solid material operatively interconnecting said sonic wave generator and said oscillatory fluid impelling pumping member, said column being adapted to transmit alternate waves of compression and tension longitudinally therethrough from said generator to said pumping member, said elastic column having an upper section of a given cross-sectional area, and a lower section of lesser cross-sectional area.

4. A deep well pump which includes: an oscillatory fluid impelling pumping member adapted for placement in the well, a sonic wave generator located at the ground surface, and an elastic column of solid material operatively interconnecting said sonic `wave generator and said oscillatory4 fluid impelling pumping member, said column being adapted to transmit alternate waves of compression and tension longitudinally therethrough from' sel-id vvge'neiatc saidelastic columnh sectional'arafin a. downwardly direction.

5. A deep well pump whichV includes: an oscillatory fluid impellingpuripig in'nber adapted for placement in the well, a 'sonic wave generator located at the ground surface, andan elastibcoli' umn of solid material-operatively interconnecting d oscilllatorycompression and tension longitudinally therethrough from said generator to said pumping member, said elastic column having a reduction in modulus of elasticity in a downward direction.

6. A deep well pump which includes: a pump tubing of elastic material, an oscillatory checkvalved fluid impelling member rigidly secured in the lower portion of said tubing, and a sonic wave generator at the ground surface operatively connected to said pump tubing and adapted to transmit alternating waves of compression and tension longitudinally down said tubing to said uid impelling member to oscillate the same, said pump tubing comprising an upper section 0f a given cross-sectional area and stiffness per unit length, and a lower section of lesser cross-sectional area and stiffness per unit length.

7. A deep -well pump which includes: la pump tubing of elastic material, an oscillatory checkvalved fluid impelling member rigidly secured in the lower portion of said tubing, and a sonic wave generator iat the ground surface operatively connected to said pump tubing and adapted to transmit alternating waves of compression and tension longitudinally down said tubing to said fluid impelling member to oscillate the same, said pump tubing comprising `an upper section of a given modulus of elasticity, and ia lower section of lesser modulus of elasticity.

8. A deep well pump which includes: a pump tubing, an oscillatory check-valved fluid impelling member rigidly secured in the lower portion of said tubing, a string of rods inside said tubing openatively interconnected lwith said uid impelling member and extending therefrom to the ground surface, said string of rods having a reduction in cross-sectional area in .a downward direction, and a sonic wave generator at the ground surface Voperatively interconnected with the upper end of the rod string and adapted to trlaIlS- mit alternate waves of compression and tension longitudinally down said string of rods to oscillate the lower end portion of the rod string :and said fluid impelling member, said reduction in crosssectional area of said rod string serving to augment the amplitude of oscillation of the lower end portionV of the rod string land of said oscillatory fluid impelling member.

9. A deep well pump which includes: a pump tubing, an oscillatory check-valved fluid plunger slidably mounted in the lower portion of s-aid tubing, a string of rods inside said tubing operatively interconnected with said plunger and extending therefrom to the ground surface, said string of rods having a reduction in cross-sectional area in a downward direction, and a sonic wave generator at the ground surfiace operatively interconnected with the upper end of the rod string, and adapted to transmit alternate waves of compression and tension longitudinally down said string of rods to oscillate the lower end portion of the rod string and said plunger, said reduction in cross-sectional aree, of said rod string serving to augment the amplitude of the oscil- 11 lation of the lower end portion of the rod string Number and of said oscillatory plunger. 1,941,593 ALBERT G. BODINE, JR. 2,056,513 2,232,678 REFERENCES CITED 5 2,355,618. The following references are of record in the 2,444,912 le of this patent:

UNITED STATES PATENTS Number Number Name Date 10 146,436 1,730,337 Bellocq Oct. 1, 1929 Name Y Date Bellocq Jan. 2, 1934 Gambarino Oct. 6, 1936 Dickinson Feb. 25, 1941 Bodine Aug. 15, 1944 Bodine July 13, 1948 FOREIGN PATENTS Country Date Great Britain 1920 

